Physics

1. Physics 9/3-6/14

2. Today’s Agenda • We will summarize the scientific method and how it is applied to a variety of situations. • I will discuss with my table mates possible Mythbusters myths to investigate

3. Definitions (p. 6) • Science is use of evidence to construct testable explanations & predictions of natural phenomena, as well as the knowledge generated through this process. • Some questions are outside the realm of science because they cannot be “scientifically” tested.

4. Definitions (cont.) • Law – • statement based on repeated experimental observations that describes some aspect of the world • Theory – • based on natural or physical phenomena, • capable of being tested • Well established, highly reliable explanations • Subject to change as new areas of science or technologies are develped

5. Definitions (cont.) • Hypothesis – A tentative & testable statement. • written in an “If”…”then” format. • If I do not do my homework, then I will fail Physics. • Model- • A representation of a an object or a system

6. Scientific Method (cont.) • Observe • Hypothesis • Experiment • Get Data • Analyze • Accept/Reject Hypothesis • Conclusion Talk among your table mates, Would scientist prefer their experiment to accept or reject their hypothesis & why?

7. Closure • Discuss with my table mates possible Mythbusters myths to investigate.

8. Physics 9/4/14

9. Starter • In YOUR OWN words, how is a theory different than a law?

10. Today • We will compare and contrast different types of scientific investigations. • I will draw a Venn diagram illustrating the 3 types of investigations as an exit ticket.

11. Agenda • Parts of an experiment • Types of Investigations • Types of Variables • Mythbuster’s Video & Questions

12. Types of Investigations • Experimental Example: How does the amount of potato affect its reaction with a fixed amount of hydrogen peroxide? - Has a dependent and independent variable -A control group is needed -Must include an experiment -Starts with a hypothesis -Requires Collecting Data -A test is designed to prove/disprove a hypothesis

13. Types of Investigation • Descriptive/Observational Example: What happens when a piece of potato is added to hydrogen peroxide? -Uses Observation to collect data -Data describes what is observed qualitatively or quantitatively -Does not require an experiment -Starts with a hypothesis -Requires collecting data

14. Types of Experiments • Comparative Example: Which vegetable shows the greatest reaction with hydrogen peroxide? -Collect data on two or more objects and make a comparison -May require an experiment -Starts with a hypothesis. -Requires collecting data.

15. Card Sort • Using the cards at your table, sort & match the type of experiment with the correct examples

16. Experimental Design or How I do my experiment.

17. Experimental Design • Variables • The Independent variable(I am in charge of) is the variable that is intentionally changed in the experiment, • The Dependent variable (changes as a result of my actions) is the variable that responds to the changes in the independent variable. • The Controlis the standard against which the researcher compares the results from each treatment group (level) in the experiment. (nothing is changed, stays the same)

18. Raindrops keep falling on my head... Answer the given questions in your journal.

19. ClosureHow are the 3 types of experiments similar?How are they different? Descriptive Experimental Comparative

20. Physics 9/5/13

21. Starter • Label the following investigations as descriptive, comparative, or experimental. • Which brand of hairspray has the strongest hold? • How do Asian Elephants raise their young? • What happens to electrons when they are slammed together at extremely high speeds? • Do antacids neutralize battery acid? Use .25g, .40 g, and .5 grams and compare to a control with no antacid.

22. Today • We will generate the equations to determine the height of objects • I will calculate the height of objects given 2 out of the 3 factors needed Agenda Examples of “Mythbuster” Experiments Mythbuster Info sheet SOHCAHTOA Practice Problems

23. “Mythbuster” Info Sheet • You may work by yourself, in a pair (2) or in a group of 3. • You need to decide on what you are investigating, how you are going to investigate & who you will be working with. • I will be checking this information on Monday

24. Mythbuster Experiment Examples • Different brands of soda react the same when Mentos are dropped in them. • Tic-Tacs cause the same reaction as Mentos when dropped in coke. • Plants grow better when played soothing music. • A plant can’t grow when it is watered with soda. • Zip-lock bag with water can repel flies. • Cologne makes a person appear more attractive. • A hardboiled egg spins differently than a raw egg. • Cotton makes the best cushion for an egg. • Different colors of M&M’s taste differently. • Most of our taste sense comes from our taste buds. • Bowling balls sink in water. • The more tension in a string the higher the pitch. • Store brand paper towels are less absorbent than name brands. • Boys can throw farther than girls. • Clip on repellent works as well as spray on repellent.

25. Direct vs. Indirect Measurement • Direct measurement is when you use a measuring device to manually take a measurement. • Indirect Measurement is when you use Math to solve for a measurement.

26. What do you already know about the Pythagorean Theorem ? If the length of one side of a right triangle was 3 m and another was 4 m, the length of the hypotenuse would be…

27. Right Triangles • Right triangles have one angle that is 90°. • They can be solved using Pythagorean Theorem. • Pythagorean Theorem => a2+b2=c2 c a b

28. Theta Θ • The Greek letter theta (Θ) is used to describe an angle. Θ

29. Scientific Calculator • If you have a scientific calculator start bringing it to class. If you have it, get it out • Some of you may have phones that already have a scientific calculator on it. • If you do not have a scientific calculator, you can download a free app for one. • Do so now.

30. SOH CAH TOA • SinΘ = Opposite/ Hypotenuse • Cos Θ = Adjacent / Hypotenuse • Tan Θ = Opposite/ Adjacent You can manipulate the formula to solve for what you need! I call it flip flopping… Θ

31. Sample Problem #1 • Want to find Y • Have • angle & adjacent • Want • Opposite Tan Θ = Opposite/ Adjacent Opposite = TanΘ x Adjacent Y = Tan 35.0 x 9.00 m Y = .5735… x 9.00 m Y = 5.16 m

32. Sextant We will use sextants to take indirect measurements of the bleachers at the football field.

33. Sample Problem • What is “X” • X = Opposite • Use “TOA” • Tan Θ = Opposite/ Adjacent • Opposite = Tan Θx Adjacent • O = 1.96 x 50 m • O = 98 meters • BUT…. • Need to add 1 meter for height • Height of tower = 98 m + 1 m • Height of tower = 98 m + 1 m

34. Now you try…How tall is the Palm Tree? 2m

35. Compare your answer with your table mates 2m

36. Problem One 1.5 m

37. Problem 1 1.5 m

38. Problem Two 3 m

39. Problem Three 5 m

40. Problem Four

41. Problem Five

42. Problem Six 0.5 m

43. Closure • Compare your answers with your classmates.

44. Physics 9/5/13

45. Today • We will record the angle & distance to the bleachers. • I will use the data gathered today to determine the height of the bleachers indirectly.